The present invention relates to a method and apparatus for rotor unbalance determination and more particularly, but not exclusively, such determination with respect to rotors secured upon shafts used in turbine engines.
Rotating shafts are used in a wide range of machines and engines. In order to avoid overstressing and simply to achieve operational efficiency, it is desirable to provide rotational balance of the rotor. Unfortunately, particularly with regard to turbine engines, these shafts must operate at a number of different rotational speeds and therefore, it is difficult to accurately determine residual unbalance within a rotor independently of rotor spin speed.